No major deleterious effects of the converters themselves could be identified, provided that the converters are well offshore. (Energy Paper 42, Department of Energy and the Energy Support Unit at Harwell.)
Some of us who are critical of official policy have always suspected that the Government supported wind farms on land because it knew that in a crowded island they could never develop sufficiently to become a major supplier of the grid, and would not, therefore, be demanding of large-scale investment. The only way that wind power could be extended sufficiently would be by building the wind turbines offshore - if you were going to go to sea, the natural thing to harvest would be the energy of the waves, which are a concentrated form of the wind.
The writer is author of 'Energy from the Waves' (Pergamon, 1981; OUP forthcoming).